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// { dg-options "-w" }
// taken from https://github.com/rust-lang/rust/blob/e1884a8e3c3e813aada8254edfa120e85bf5ffca/library/core/src/cmp.rs#L98
#[lang = "sized"]
pub trait Sized {}
#[lang = "eq"]
#[stable(feature = "rust1", since = "1.0.0")]
#[doc(alias = "==")]
#[doc(alias = "!=")]
pub trait PartialEq<Rhs: ?Sized = Self> {
/// This method tests for `self` and `other` values to be equal, and is used
/// by `==`.
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
fn eq(&self, other: &Rhs) -> bool;
/// This method tests for `!=`.
#[inline]
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
fn ne(&self, other: &Rhs) -> bool {
!self.eq(other)
}
}
enum BookFormat {
Paperback,
Hardback,
Ebook,
}
impl PartialEq<BookFormat> for BookFormat {
fn eq(&self, other: &BookFormat) -> bool {
self == other
}
}
pub struct Book {
isbn: i32,
format: BookFormat,
}
// Implement <Book> == <BookFormat> comparisons
impl PartialEq<BookFormat> for Book {
fn eq(&self, other: &BookFormat) -> bool {
self.format == *other
}
}
// Implement <BookFormat> == <Book> comparisons
impl PartialEq<Book> for BookFormat {
fn eq(&self, other: &Book) -> bool {
*self == other.format
}
}
// Implement <Book> == <Book> comparisons
impl PartialEq<Book> for Book {
fn eq(&self, other: &Book) -> bool {
self.isbn == other.isbn
}
}
pub fn main() {
let b1 = Book {
isbn: 1,
format: BookFormat::Paperback,
};
let b2 = Book {
isbn: 2,
format: BookFormat::Paperback,
};
let _c1: bool = b1 == BookFormat::Paperback;
let _c2: bool = BookFormat::Paperback == b2;
let _c3: bool = b1 != b2;
}
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